Closure and closure operator for vehicle hoists



H. D. SMITH April 15, 1952 CLOSURE AND CLOSURE OPERATOR FOR VEHICLE HOISTS 5 sheets sheet 1 Filed July 3, 1948 INVENTOE Harry 0. Smif/z H. D. SMITH April 15, 1952 CLOSURE AND CLOSURE OPERATOR FOR VEHICLE HOISTS Filed July 5, 1948 5 Sheets-Sheet 2 INVL'W roe Harr 0 Smhh XAWM H. D. SMITH April 15, 1952 CLOSURE AND CLOSURE OPERATOR FOR VEHICLE HOISTS 5 Sheets-Sheet 5 Filed July 3, 1948 I NVEN r02 Harry 0 Smif/z W/F f Patented Apr. 15, 1952 CLOSURE AND CLOSURE OPERATOR FOR VEHICLE HOISTS Harry D. Smith, Philadelphia, Pa., assignor to Globe Hoist Company, Des Moincs, Iowa, a corporation of Iowa Application July 3, 1948, Serial No. 37,012

Claims. 1

This invention relates generally to vehicle hoists and in particular to a pit closure means for a vehicle hoist having a lift member mounted in a floor pit for movement to a lowered position below the level of the floor surface. Pit mounted vehicle hoists of this type provide for the pit being completely covered when the lift member is lowered therein, so that the space occupied by the hoist is unobstructed for the free travel of vehicles and garage equipment thereover when the hoist is not in use.

It is an object of this invention to provide an improved vehicle hoist of pit mounted type.

A further object of this invention is to provide an improved pit closure means for a pit mounted hoist.

Another object of this invention is to provide a pit mounted hoist of a full hydraulic type having an oil reservoir adapted to receive air under pressure to raise the lift member, in which an air valve has an actuating lever connected with a pit closure means through a lost motion mechanism such that the closure means is closed when the actuating lever is in a neutral position, and is moved to a pit open position in response only to the movement of the actuating lever to a position providing for the exhaust or release of air from the oil reservoir.

A further object of this invention is to provide a pit closure means for a pit mounted hoist which is of a simple and compact construction, efiicient in operation so as to always be in an open position when the hoist is tobe lowered into the pit, capable of being opened by the hoist as the hoist is raised from the pit, and

adapted to operate over prolonged periods of time with a minimum of service and maintenance attention.

A feature of this invention is found in the provision of a pit mounted hoist of a full hydraulic type in which a pair of oppositely arranged pit cover members are supported on opposite side walls of the pit for pivotal movement toward each other to a pit closing position. A rock shaft, supported within the pit, is extended between and connected with the cover members so that the cover members are concurrently movable in response to a rocking movement of the shaft. An air pressure system, connected with an oil reservoir for the lift member of the hoist, includes a valve unit for controlling the admission of air under pressure to and the re lease of such air from the oil reservoir. A manually actuated handle for the valve unit is connectedthrough a lost motion connection with the rock shaft so that the closure means is opened when the handle is actuated to provide for a release of air under pressure from the reservoir, and closed when the handle is actuated to a neutral position at which the air valve unit is closed. The handle is ineifective to operate the rock shaft, when the handle is moved to a position providing for the admission of air under pressure to the reservoir.

Further objects, features and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawings, in which:

Fig. 1 is a perspective view of a vehicle lift of two post type embodying the pit closure means of this invention, with certain parts being broken away and with the pit closing doors for the front hoist being illustrated in their open positions to more clearly show the construction of the closure means;

Fig. 2 is an enlarged sectional detail view taken on the lines 2-2 in Fig. 1, showing a portion of the closure actuatingmeans for the front hoist;

Fig. 3 is an enlarged plan view of the rear hoist showing the closure means therefor in a. pit closing position, but with certain parts broken away;

Fig. 4 is an enlarged fragmentary perspective view of the rear hoist looking in a direction generally upwardly and rearwardly, and with the pit closure means in a closed position;

Fig. 5 is an enlarged sectional detail view taken substantially along the line 55 in Fig. 1;

Figs. 6 and '7 are enlarged sectional views of an air valve unit as seen on the lines 6-6 and (-1, respectively, in Fig. 5;

Fig. 8 is a vertical longitudinal sectional view of the air valve unit shown in Fig. 6; and

Fig. 9 is a diagrammatic showing of the air and oil systems for the hoist.

With reference to the drawings, there is shown in Fig. 1 an automobile hoist of two-post type including front and rear hoists, with the front hoist having a cylinder I5 operatively associated with a piston or lift member l6 and the rear hoist including a cylinder I1 and associated piston 18.

The front hoist is located in a pit 19 formed in floor surface, indicated generally 29, and includes a front axle supporting structure or saddle 2|, of a substantially U-shape, fixed to the top of the piston iii and having a raised axle-engaging rib 22 at the free end of each of its legs. J... 23 for engaging automobile spring pads are e tended outwardly from the axle engaging ribs 22.

The opening at the top of the pit i9 is of a size and shape such that the saddle member 2!, at the lowermost limit of travel of the piston 56, is received within the pit below the surface of the floor 26. With the saddle 2! thus located within the pit l9, the pit opening is closed by a pair of floor or cover plates 25 and 26 having their outer sides pivoted at 2'! on opposite side walls or the pit !9, for pivotal movement upwardly and away from each other to their open positions, shown in Fig. 1, and for movement downwardly and toward each other to closed and supported positions on the ribs 22. The cover plates 25 and 35 are'provided at one of their ends with meshed gear segments 28 whereby the covers are concurrently movable in response to the pivotal movement of one thereof, for a purpose which will appear later. r

The rear is mounted in a ilocr pit 29 .(Fig. 1) and inc es a rear axle SI. erting structure having a t ansversely extended tabular beam member 3% fixed at its central portion to the top of the piston 255. Each end ci the tubular beam 31 carries a fiat upright longitudinally extended supporting member Slidably carried on the top edge of her 32, for movement longitudinally thereof, is a rear axle engaging blockBS. 7

Adapted to rest on the top of the tubular beam 3!, at a position above the piston ill, is a vertically movable cover plate 3 3 of a circular shape. The plate 34 is guided for up and-down movement by a pair of extensions 36, one of which only is shown in Fig. 1, arranged at opposite sides of the piston l3 and extendible through the tubular beam member 3i. 7 p

The opening of he rear pit 29 is of a size and shape such that when the piston leis at its lowermost limit of 'av l, the rear axle supporting structure is receivable therein at apositio n below the level of the door 253. A closing of the pit opening, when therear hoist is in either a lowered or raised position,.isaccomplished by the provisionof means including a pair of stationary cover members 3'! and 38.

With reference to Figs. 1 and 3, it is seen: that the cover plates 3.3 and 3*. are of a substantially rectangular shape with their innerends 3S spaced apart from each other to form a transverse opening l! adapted to receivethe transverse beam member 3! therethrough. The outer ends of the cover plates 3'! and 38 are pivoted at Q2 to the. opposite end walls of the pit opening 23. The opposite-sides 43 or" the cover .platessl and 38 are spaced from the adjacent sidewalls i lof the pit iii to form longitudinally extended openings 46,

open to the opposite ends of the transverse opening ii and adapted to. receive the support members 32 therein. Each plate 31 and 38, adjacent its inner end, carries a pair of downwardly proiected support rods 4'! (Figshl and 4) the lower ends of which rest on a square shaped flange member 48 mounted about the top of the cylinder E1. The plates 3? and 38 are thus firmly supported in positions substantially flush with the' ach upright sup-porting rnemlongitudinally extended pivoted cover members.

'59 havinglateral ears or extensions 5| projected upwardly and away from each other by the axle blocks 33 whereby to open the longitudinal openings 45 and the transverse opening 4|. During this raising of the rear hoist, the cover plate 34 iswithout movement until it is engaged and carried upwardly by the transverse beam member 3|.

When the hoist is elevated to a position such that the supportmembers 32 are out of engaging positions with the covers 49, the cover members &9 are returned to their closed positions by gravity, as illustrated in Fig. 1, whereby a garage or service man is free to move about below the rear hoist without danger of slipping into the pit 23.

'When the rear hoist'is to be lowered, the pivoted'covermembers '49 are initially [moved to their open positions to provide for the'l5'a-SSa e of the cross member 3 l. and the support members 32 within the spaces 4| and 45, respectively. On a lowering of the rear hoist within the'pit 29, the cover plate 34 is engaged in a supported position on'the stationary cover members 31 a'ndj38. When the rear hoist 'is lowered entirely within the pit 29 below the level of the floor surface 20, the pivoted covers 48 are moved to their" closed positions by the action of gravity. v Thus, as clearly appears in Fig. 3, when the rear hoist is in a, lowered position within the pit 29; the'stationary cover memberstl and 3.8,"thepivoted covers 49, and the vertically movable coverfplate 34 cooperate to completely close the pit opening 29. The pivoted covers 49 are operatedbyimeans including a rock shaft 56 '(Figs. 1 and') which is rotatably supported in a pairof oppositely arranged bearing members 51 'proje"cted"downwardly from the 'cover plate 33st positiohs 1adjacent' to the rear end of such cover plate. The opposite ends of the rock shaft 55 project outwardly from the bearings 5i a'ndjterminate at positions below thepivoted cover plates 49,1'Rock arms 58, at the ends of the rock sha'ft BL are pivotally connected at 53 to'levers'orlinks '61, which in turn are pivoted at" as Ito, the pivoted cover members 49.. It is seen, therefore, thatthe pivoted cover members 45' are'mcvablyconnected together for concurrent pivotal movement in response to a rocking action of the shaft 56.

This rocking'action of the shaft 56' is accomplished manually by means including a manually actuated control rod '62 (Figs. 1 and 5) which is connected at B3to' a rock arm 64 mounted? on the rock shaft 55. The rear end E6 of the'jcontrol rod 62 is connected through a lost motionmechanism, designated generally'as 61,'wi'th' a valve mission of oil'under pressure to the 'cylinde'rs l5 and, H, respectively, are connected in the oil supply lines l2 and 13, respectively, at positions .adjacentjtoje'ach other; The control handles l8 and 19,'for the valves 16 and 11, respectively; are

'i'elatively constructed and arranged so as to be capable of being gripped and operated by one hand for simultaneous operation of the lift members I8 and I8. I I

Air under pressure is supplied to the oil reservoir H from a suitable source of supply 80 (Fig. i

9) through air lines 8| and 8la. The air valve unit 59, which controls the admission of air to and the release of air from the oil reservoir II, is connected between the air lines 8| and Bla.

The air valve unit 89 (Fig. 8) includes a pair of like valve members 82 and 83 arranged at opposite sides of a pair of transversely spaced pivot supports 84 projected upwardly from the housing or casing 85 of the valve unit 69. A valve actuating'member 85, of a substantially V-shape. is pivoted at 8"! between the supports 84 and has its free ends 83 arranged so as to alternately engage the valve stems89 and 9| for the valve members 82 and 83, respectively.

The handle 88 is pivoted at 92 between the upper ends of the supports 84 and is integrally formed adjacent its pivoted end with oppositely arranged pairs of locking members 93, adapted to releasably engage therebetween coactinglocking members 94 formed on the actuating member 86 at positions adjacent to the free ends 88 thereof. I The casing 85 is formed with a longitudinally extended air passage 98, common to the valve members 82 and 83, and provided between such valve members with a connection 91, which is connected with the oil reservoir II through the air line 81a.

When the operating handle 88 is in its neutral or central position, shown in fulllines in Fig. 8, both of the valve members 82 and 83 are closed and the actuating member 88 is out of contact engagement with the valve stems 89 and 9|. To admit air under pressure to the oil reservoir 1|, the handle 68 is moved in a clockwise direction to its dotted line position indicated at A in Fig. 8. This movement of the handle 88, through the actuating member 86, depresses the stem member ill 'to open the valve member 83. Air under pressure is thus admitted from the air line 81 through the valve 83, passage 95 and air line Mo to the oil reservoir II.

It is to be noted that the lift members It and I8 are not operated on this manipulation of the handle 58, by virtue of the fact that the oil valves 16 and T7 are closed. To maintain th oil in the reservoir II under pressure the handle 88 is returned to its neutral position.

When air is to be released from the oil reservoir, the handle 68 is moved in a counter-clockwise direction from its full line position shown in Fig. 8, to its dotted line position indicated at 13, whereby the valve member 82 is opened. Air from the reservoir 1| is thus permitted to flow through the line 8Ia, passage 96 and valve 82 to the atmosphere through an exhaust outlet 98 formed in the valve casing 85. This release or exhaust of air is stopped by returning the handle 59 to its neutral position.

As best appears in Figs. 1 and 5, the air valve unit 69 and the oil valves 16 and 11 are arranged in a floor pit 99 located rearwardly from the floor pit 29 with the handles 68, 18 and 19 being arranged adjacent to each other at positions near member I06 horizontally arranged in a straddling relation with the air valve unit 69. The U-member I96 forms part of the lost motion mechanism 61. The rear or free ends I9! of the legs of the U-member I88 are pivotally connected at )8 to the lower ends of a pair of upright pivoted levers I09 positioned at opposite sides of the pivot supports 84, and pivoted intermediate their ends on the pivot 92 for the handle 68 (Figs. 5, 6 and 7).

The rear sides of the members I99, near the upper ends thereof, are formed with notches I I I to receive a pair of oppositely arranged pins II2 which are extended laterally in opposite directions from the handle 88.

On movement of the handle 68 toward the right, as viewed in Figs. 5 and 3, to open the valve 83 and admit air under pressure to the reservoir II, the pins H2 are moved out of the notches I II so that no movement is imparted to the control rod 62 in response to a movement of the handle 88. On actuation of the handle 19 for the oil valve Ti, to elevate the lift member l8, the covers 49 are engaged and moved to their open'positions by the upward movement of the. axle blocks 33. On elevation of the blocks 33 and upright supports 32, out of engaging positions with the covers 49, the covers 49 are moved to their closed positions by the action of gravity.

When the lift member is to be returned to a lowered position within the floor pit 28, on actuation of the handle 68 toward the left, as viewed in Fig. 5, or from its full position to its dotted line position B, shown in Fig. 8, the levers I99 are engaged by the pins H2 whereby the control rod 62 is moved rearwardly, or to the right, as viewed in Fig. 5, to in turn provide for a rocking movement of the rock arm 64 from its full line position to its dotted line position, also shown in Fig. 5. This pivotal movement of the rock arm 64, through the rock arms 58 and levers 6|, provides for a concurrent upward movement of the pivoted covers 49 to their open positions. These open positions of the covers 49 are maintained until the handle 68 is returned to its neutral position. The levers I99 follow the handle 68 to its neutral position, in response to the downward movement of the covers 49 by the action of gravity.

It is seen, therefore, that on the admission of air under pressure to the oil reservoir H, the pivoted covers 49 remain in their closed positions, and that on movement of the handle 88 to release air from the oil reservoir 'iI, the pivoted covers 49 are manually moved to their open positions in response to the manipulation of the handle 68. The lost motion mechanism 61 thus provides for a manual actuation of the pivoted covers 29 in response only to the movement of the handle 88 to open the valve 82.

The cover members 24 and 29 for the front lift member 16 are operated concurrently with the rear pivoted covers 49 by extending the con- 'trol rod 62 through an opening I2I extended be tween the front pit I9 and the rear pit 29. The front end I22 of the control rod 82 (Fig. 2) is pivoted at I23 to a crank arm I24 projected downwardly from the cover plate 24 at a position forwardly of the cover pivot 21. On a rearward movement of the control rod 82, in response in Fig. 2. The rear cover plate 26 is concurrently moved to its open position by virtue of the meshed engagement of the gear segments 28. On movement of the handle Bil-to itsneutral position, ,the covers 24 and26are moved to their closed'positionsby the action of gravity.

It is seen, therefore, that the front covers and 26, and rear pivoted covers 49 are connected together through the control rod 62 for concurrent movement in response to an operation of the handle ,68 for the air valve unit 69. It is to be noted also that the front cover plates Hand 2 6,'when the liftmember i6 is elevated from the 'fioor pit I9, are engaged and moved by the saddle member 2| to their open positions. Further, the control rod 62 is arranged relative to the front and rear hoist frame structures soas to be in a clearance relation therewith when the hoists, are "in lowered positions within their respective floor pits.

From a consideration of the abovedescription. it is seen that the invention provides a closure "means for a full hydraulic hoist of pit-mounted type, in which the closure means, on a raising A, of the hoist lift members, are engaged and moved by said lift members to their open positions. On a manipulation of the control handle 68'for the air valve unit 69, to exhaust air from the oil reservoir H to lower the lift members, the cover members are movable in response to a movement of the handle 68 to their open positions. A 'C10Slng of the pit closure means, both after the hoist is-elevated from the pit, or lowered within the'pit, takes place by the action of gravity.

Although the invention has been described and illustrated with respect to a full hydraulic-hoist, inwhich air under pressure is applied on the'oil supplied to the cylinders for the lift members, it is to be understood that it is readily applicableto hoists of pump operated type; namely, in which 011 under pressure is supplied directly to the lift members from a pump unit or the like, by mere-,

ly connecting the valve unit 69in the oil supply line to the lift cylinders.

Further, although the invention-has beendescribed andillustrated with respect toa' preferred embodiment thereof, it is to be understood that'it'is' not to be so limited since changes and modifications can'be made therein'which' are within the full intended scope of this invention, as defined by the appended claims.

' Iclaim:

1. In a full hydraulic hoist having a lift member mounted in a floor pit and movable to a lowered position within the pit, means-for closing said pit including a pair of oppositely arranged cover members pivoted on'side walls of said pit for pivotal movementtoward each other to pit closing positions, movable means in said pit connecting said cover members together for concurrent pivotal movement, means" for raising and lowering said lift member including an oil reser-' voir and a source of air under pressure, anair connection between said reservoir and said source of air including a valve unit having valve members for admitting air'to and releasing airfrom saidoil reservoir, a pivoted actuating member for said a'ctuatinglever" with said movable means: torprovide for an opening movement of said cover members concurrently with the release ofairnn- 'necting said cover members together for concurrent pivotal movement, means for raising and lowering said lift member including a fluid control system having a sourceof fluid under, pressure, a valve unit in said fluid system for controlling the admission and release offluid under pressure to said lift member, an actuating lever for said valve unit, and means connecting said movable means with said lever for movement in response to said lever such that said cover members 'are opened when said lever is moved to release high pressure fluid from said lift member.

.3. In a full hydraulic hoist having a lift member mounted in a floor pit and movable to alowered position within the pit, means for closing said pit including a pair of oppositely arranged cover members pivoted on opposite side :walls of said pit for pivotal movement toward each other to pit closing .positions, means within said pit connecting said cover members togethe for concurrent pivotal'movement, means for supplying fluid under pressure'to said lift member,.valve means for controlling the admission and release of fluid under pressure to said lift member, including a manually actuated lever, and means connecting said'lever with said cover connecting means such that said cover members are pivotally moved to open positions in response to a movement of said lever to release fluid under pressure from said lift member.

4. In a full hydraulic hoist having a lift member mounted ina floor pit and movable to a lowered' position-within the pit, means for closing said pit including a pair of oppositely arranged cover members pivoted on opposite side walls of said pitymeans within said pit connecting said .cover members together for concurrent'pivotal movement including a rock shaft extended between said cover members, said covers being pivotally movable toward each other to pit closing positions, means for supplying fluid under pressure to said lift member to raise and lower the same including a fluid reservoir, means for applying and releasingair under pressure on the fillld V in said reservoir including a valve unit having an actuating handle, and means connected between said handle and said rock shaft to provide for a -movement of said cover members to pit opening positions on actuation of said handle to release air from said reservoir. 7

5. In a full hydraulic hoist having apair of lift members mounted in floor pits and movable to lowered positions within the pits, means for closing said pits including a pair of'pivoted cover members for each of said pits movable inwardly toward each other to pit closing positions, movable means interconnecting said cover' members for concurrent pivotal movement, means for raising and lowering said lift members includinga fluidsystem, means for applying a pressure on the fluid in said system, valve means for controlling the application and release'of said fluid pressure on said liftmembers, includingan actuatingmem- 9 10 her, and means connecting said actuating mem- REFERENCES CITED bar with said movable means such that said cover The following references are of record in the members are moved to pit opening positions in me of this patent: response to a movement of said actuating member to a position for releasing the fluid pressure 5 UNITED STATES PATENTS on said lift members, with said connecting means Number Name Date being ineffective to move said movable means on 2,015,357 Weaver Sept. 24, 1935 movement of said actuating member to a posi- 2,107,210 Palm Feb. 1, 1938 tion for applyin he fluid. pressure on said lift 2,464,731 Thompson Mar. 15, 1949 members. 10

HARRY D. SMITH. 

